According to Setlist.fm, these moments, which the band refers to as "doodles," have been showing up right before Trujillo's solo on "(Anesthesia) Pulling Teeth." While most of the songs are known primarily to residents of that country, a few have made their way overseas – most notably Scorpions' "Rock You Like a Hurricane," Accept's "Balls to the Wall" and Europe's "The Final Countdown." But they've also indulged a lighter side than their reputation usually allows, performing cuts like ABBA's "Dancing Queen," "Take on Me" by A-ha, Falco's "Rock Me Amadeus" and the Italian standard "Volare."

Take a look at all the surprising songs Metallica have covered below, and be sure to check back because we'll be updating this throughout the year.

May 11, Helsinki, Finland: Hassisen Kone, "Rappiolla"

For the last night of Metallica's European tour, they broke out "Rappiolla," the opening track from Täältä tullaan Venäjä (Russia Here We Come), the 1980 debut album by Hassisen Kone. Although they broke up only two years later, frontman Ismo Alanko has had a lengthy career, first with Sielun Veljet and, since 1990, as a solo act.

For the first night of their two-night stand in Helsinki, Metallica brought a special guest for the first time during the doodle: former Hanoi Rocks singer Michael Monroe. They performed "Dead, Jail or Rock N' Roll," which appeared on Monroe's 1989 solo album, Not Fakin' It. It was the first single from the record and the video featured a cameo by Axl Rose.

May 7, Stockholm: ABBA, 'Dancing Queen'

Hailing from Stockholm, ABBA broke through to a global audience when "Waterloo" won the 1974 Eurovision Song Contest. For the rest of the decade, they dominated pop charts around the world, with 1976's "Dancing Queen" being the apex of their popularity. Although they broke up in 1982, they announced in May 2018 that they recorded two new songs for a TV special and a 2019 hologram tour.

May 5, Stockholm: Europe, 'The Final Countdown'

This song's dramatic synth riff helped break Europe in the U.S., scoring the band a No. 8 hit on the pop chart; their album of the same name reached the identical position. "The Final Countdown" has remained in the public eye through its use in commercials, during sporting events and as GOB Bluth's theme song on the sitcom Arrested Development.

May 2: Fornebu, Norway: A-ha, 'Take on Me'

Hailing from Oslo, Norway, A-ha struck gold when their debut single, "Take on Me," topped the Billboard Hot 100 in 1985. The song's innovative video also won six MTV Video Music Awards. Even though A-ha had only one other Top 20 hit in the U.S., "The Sun Always Shines on T.V.," they've remained very popular in their homeland and the U.K.

April 30, Leipzig, Germany: Accept, 'Balls to the Wall'

"Balls to the Wall" was the title track to Accept's fifth album, released in 1983. The video, which featured singer Udo Dirkschneider riding a wrecking ball as it took down a clock tower, helped the album to gold status in the U.S.. It's still the only Accept record to achieve that feat.

April 28, Krakow, Poland: Dzem, 'Wehikuł Czasu'

"Wehikuł Czasu" ("Time Machine") was a 1989 single by Dzem (Jam) from their album Najemnik (Mercenary). The band formed in 1973 in Tychy, Poland, but didn't release their first record until 1985. Although original members Ryszard Riedel (vocals) and Pawel Berger (keyboards) have died, Dzem have continued with the founding guitar-and-bass brother duo of Adam and Beno Otręba.

April 26, Munich: Spider Murphy Gang, 'Skandal im Sperrbezirk'

Named after the saxophone-playing inmate in Elvis Presley's "Jailhouse Rock," the Spider Murphy Gang formed in 1977 and released their debut a year later. "Skandal im Sperrbezirk" ("Scandal in the Sperrbezirk") was their breakthrough single, going to No. 1 in Germany, Austria and Czechoslovakia in 1981. It's about a Munich hooker named Rosi working inside the "Sperrbezirk," an area were prostitution is forbidden.

"Procreation (of the Wicked)" appeared on Morbid Tales, the 1984 debut by the Swiss metal band Celtic Frost. Metallica dedicated their performance to Martin Eric Ain, the group's founding bassist, who died in October 2017. Celtic Frost combined classic metal, punk and goth, and have been cited as an influence on Nirvana. Dave Grohl collaborated with singer Tom Gabriel Fischer on one song for Probot, Grohl's 2004 solo project.

Subtitled "Coming Home," Peter Schilling continued the saga of Major Tom, the astronaut depicted in David Bowie's hits "Space Oddity" and "Ashes to Ashes." The track peaked at No. 14 in the U.S. and topped the charts in Austria, Germany, Canada and Switzerland. He had only one more U.S. hit, with "The Different Story (World of Lust and Crime)" reaching No. 16 on the dance chart and No. 61 on the Hot 100 in 1989.

In 1965, Drafi Deutscher scored a No. 1 hit in Germany with "Marmor, Stein und Eisen Bricht" ("Marble, Stone and Iron Breaks") when he was only 19. He continued to have hits through the '60s, but spent much of the subsequent decade working behind the scenes as a writer and producer (most notably Tina Rainford's Silver Bird and Boney M.'s "Belfast"), often using pseudonyms. He died in 2006 at the age of 60.

April 5, Budapest, Hungary: Tankcsapda, 'A Legjobb Mèreg'

Translated as "The Best Poison," "A Legjobb Mèreg" was the title track to a 1992 album by Tankcsapda ("Tricky"). The trio formed in 1989 in Debrecen, Hungary, and are still recording and touring, with frontman Laszlo Lukács as the sole original member.

April 2, Prague, Czech Republic: Ivan Mládek, 'Jožin z Bažin'

A novelty song by Czech musician and comedian Ivan Mládek and his Banjo Band, "Jožin z Bažin" ("Jožin From the Swamps") tells the story of a monster who terrorizes a village in Moravia and eats people from Prague. He's defeated by the song's narrator, a man who drops powder on him from a crop-dusting plane and sells him to a zoo. "It is an honor for me, since I value the American music tradition the most – although I don’t understand this music, I admit, because what I know is Dixieland," Mládek said. "But, of course, I was happy to hear that such a famous band had chosen to play the song. I am really impressed that they were able to sing in Czech.”

March 31, Vienna, Austria: Falco, 'Rock Me Amadeus'

Vienna native Falco had a slew of synth-pop hits in Austria and Germany in the '80s, but he's best remembered in the U.S. for the Mozart-themed "Rock Me Amadeus," which hit No. 1 in 1985. Although he's thought of as a one-hit wonder, he had another Top 20 hit that same year with "Vienna Calling" and was also the co-writer of "Der Kommissar," which After the Fire took to No. 5 in 1983.

Hammett has long credited former UFO guitarist Michael Schenker as a main influence, and the two traded solos earlier this year on Schenker's "Heart and Soul." When Metallica's WorldWired tour hit Hamburg, the Doodle consisted of two songs, "Into the Arena" by the Michael Schenker Group and "Rock Bottom" by UFO.

March 27, Herning, Denmark: Gasolin' 'Rabalderstræde'

Formed in 1969 in Christianshavn, Denmark, Gasolin' were one of the most popular bands in Lars Ulrich's native country in the '70s. The chart-topping "Rabalderstræde" appeared on 1975's Gas 5, but the group was unable to translate its fame to America, and they broke up three years later.

Feb. 16, Mannheim, Germany: Scorpions, 'Rock You Like a Hurricane'

In 1984, more than a decade into their recording career, Scorpions released "Rock You Like a Hurricane" on Love at First Sting. The Germany-based band, which had been steadily building an audience in the U.S., solidified its status as global superstars when the song reached No. 25 on Billboard's Hot 100 and No. 5 on the Top Rocks Tracks chart.

Feb. 14, Bologna, Italy: Lucio Dalla, 'Caruso'

Lucio Dalla was a Bologna-born singer-songwriter who first gained fame in Italy as a jazz clarinetist in the '60s. He wrote "Caruso" in 1986, and the song, dedicated to the legendary opera singer Enrico Caruso, has since been covered by Luciano Pavarotti, Julio Iglesias and Andrea Bocelli. Neal Schon recorded an instrumental version of it on 2001's Voice.

Feb. 12, Bologna, Italy: Domenico Modugno, 'Nel Blu Dipinto di Blu'

Translated as "In the Blue That Is Painted Blue," Domenico Modugno's "Nel Blu Dipinto di Blu" was Italy's entry in the Eurovision Song Contest in 1958, where it finished in third place. It has gained greater international fame, however, under its more commonly known name, "Volare."

Feb. 10, Turin, Italy: Vasco Rossi, 'C'è Chi Dice No'

Released in 1987, "C'è Chi Dice No" ("Some Say No") is the title track to the eighth album by Italian singer Vasco Rossi. The record, which came a few years after he spent three weeks in prison for cocaine possession, was considered his comeback, spending 12 weeks at No. 1 in the Italian chart.

Feb. 7, Barcelona: Peret, 'El Muerto Vivo'

Written in 1965 by Colombian composer Guillermo González Arenas, "El Muerto Vivo" ("The Dead Alive") was recorded a year later by Pedro Pubill "Peret" Calaf in a style that came to be known as "Catalan rumba." Its lyrics tell the story of a man who had gone missing and was presumed dead – there was even a wake held in his honor – before he suddenly resurfaces in town after a week of partying.

Feb. 5, Madrid: Barón Rojo, 'Los Rockeros Van al Infierno'

Another metal band from Madrid, Barón Rojo took their name from the German World War I flying ace Manfred von Richthofen (famously nicknamed the "Red Baron"). "Los Rockeros Van al Infierno" ("The Rockers Go to Hell"), one of their most famous songs, was found on their second album, 1982's Volumen Brutal.

Feb. 3, Madrid: Obús, 'Vamos Muy Bien'

Founded in Madrid in 1981, Obús are one Spain's biggest heavy metal bands. "Vamos Muy Bien" (roughly translated as "We're Doing Very Well") appeared on 1984's El Que Mas. "In the name of Obús, we want to thank Metallica for the detail of playing the legendary 'Vamos Muy Bien' in their concert last weekend in Madrid," the band said in a statement. "For us, it is an honor to listen to our music in the hands of one of the biggest bands in the world. You are a great band and great people. A hug and long live rock!"

Feb. 1, Lisbon, Portugal: Xutos e Pontapés, 'A Minha Casinha'

On the first night of the tour's European leg, Metallica covered "A Minha Casinha" ("My Little House") by a Portuguese punk band that formed in 1978 and is still active. They dedicated it to Zé Pedro, the band's founding guitarist, who died on Nov. 30, 2017.